Ferroelectric transitions in monolayer $\beta$–In${}_2$Se${}_3$ grown on bilayer graphene were studied using low energy electron diffraction and scanning tunneling microscopy methods. Violation of the electron dispersion during transitions was studied using angle-resolved photoelectron spectroscopy. In contrast to the bulk case, we observed coexistence of stripe (${\beta }^{\prime }$) and zigzag (${\alpha }^{\prime }$ ) phases in the low temperature limit. Experimental results were confirmed by total energy calculations of the corresponded structures that were found using ab initio random structure searching technique. As total energies of antiferroelectric ${\beta }^{\prime }$ phase and ferroelectric ${\alpha }^{\prime }$ phase are almost the same, monolayer In${}_2$Se${}_3$ appears to be promising material for the ferroelectric switching devices.

单层中的铁电跃迁 $\beta$-在${}_2$硒${}_3$使用低能电子衍射和扫描隧道显微镜方法研究了在双层石墨烯上生长的。使用角分辨光电子能谱研究了跃迁期间电子色散的破坏。与散装情况相比，我们观察到条纹的共存（${\beta }^{\text{'}}$) 和之字形 (${\alpha }^{\text{'}}$) 阶段在低温极限。实验结果通过使用从头随机结构搜索技术发现的相应结构的总能量计算得到证实。作为反铁电体的总能量 ${\beta }^{\text{'}}$相位和铁电体 ${\alpha }^{\text{'}}$相几乎相同，单层In${}_2$硒${}_3$似乎是用于铁电开关器件的有前途的材料。